i just loaded mint 6 up on to my computer (dell latitude d620) and my on-board NIC can ping but i can't browse with firefox, or download anything.also, the drivers for my wireless interface weren't even installed. you can see it through iwconfig, but it comes up as down through ifconfig.so i typed ifconfig wlan0 up to bring it up but i get an error saying the device isn't there. so because of that i think it's the driver.

Assuming you have windose on that computer you will probably find the driver on the windose partition in Windows>Driver Cache ending with .inf . You could go to the Control Panel and use "Windows Wireless Drivers" to install the driver and browse to the driver location in windose or copy it to your desktop and browse to it there.